The remarkable hydrothermal features in Lassen Volcanic National Park include roaring fumaroles (steam and volcanic-gas vents), thumping mudpots, boiling pools, and steaming ground. These features are related to active volcanism and are indications of the ongoing potential for further eruptions from the Lassen “volcanic center.” The hottest and most vigorous hydrothermal features in Lassen Volcanic National Park are at Bumpass Hell and we recently had the opportunity to explore this area for ourselves.
All four types of volcanoes found in the entire world are represented in Lassen Volcanic National Park. Volcanoes found in the park include shield (Prospect Peak), plug dome (Lassen Peak), Cinder Cone (Cinder Cone), and Composite (Brokeoff Volcano) volcanoes. Hands-on models of each volcano type are accessible in the visitor center as well as numerous historical photographs, interactive maps, and of course the park film.
The Lassen region is at the south end of the Cascade chain of volcanoes. Steam vents and hot springs are surface expressions of hydrothermal systems, in which cold surface water percolates deep into the ground, where it is warmed by the slow release of thermal energy from a heat source. The Lassen volcanic center is host to such a system because it has the three required elements—abundant ground water, permeable rock, and a heat source at depth. The vigor of Lassen’s hydrothermal features varies both seasonally and from year to year.
The kids completed a scavenger hunt within the exhibit hall (one of several components of the Junior Ranger program) and reflected upon previous visits to Lassen. In addition, they completed a few of the activities outlined in the Volcano Club guide available on the park website. We live within a days drive, so we’ll be back again soon to further explore this dynamic national treasure and to complete the Junior Ranger program.
A 500 mile volcano to volcano driving guide highlighting the geology that shaped the land from Lassen Volcanic National Park in Northern California and ending at Crater Lake National Park in Southern Oregon is available. See Volcanic Legacy Byway for a map of the geology guide and corresponding points of interest by number.